If there had been more snow, the water would be moving a little quicker and you might've gotten away with a shorter, stouter leader. As it is, you'll be banking on the fish waiting for a hopper to fall into the river with a splash, just like your fake one does when you cast it about a foot away from the bank that has held so many fish in the past. You let it dead drift back towards you, saving the twitches you'll add for later if the dead drift proves ineffective. You see her turn and follow the imitation down stream towards you and though it feels like half an hour passes, she quickly takes down your fly with a determined gulp. You wait for her head to turn back upstream before you set the hook and feel her weight.
That's why you tie hoppers in January.